In 2004, the Institute of Medicine brought national attention to the issue of health literacy, but nutrition literacy has received little attention. Nurition education for the public is a necessary preventive measure, considering the increasing rates of overweight and obesity in the United States as well as diet-related chronic diseases. Because nutrition is so important for prevention and treatment of many diseases, health professionals need to be able to assess their patients' competency with diet-related information and skills before determining their plan of care. While tools to identify health literacy are available for us in primary care settings, these tools do not adequately assess nutrition literacy. The objectives of this research application are to produce an effective tool for measuring nutrition literacy among primary care patients with chronic illness, and to identify the extent to which nutrition literacy is associated with diet quality. We hypothesize that nutrition literacy will vary substantially among patients and will be related to dietary quality. The long-term goal of this research is to improve nutrition education as a means for improving diet quality. Specific aims of this research application seek to (Aim 1) adapt the Nutrition Literacy Assessment Instrument (NLAI) (a tool we have designed for measuring nutrition literacy) for use in a primary care population; (Aim 2) estimate the NLAI's ability to produce consistent scores (reliability) and estimate its accuracy in measuring nutrition literacy (validity); and (Aim 3) estimate the ability f the NLAI to predict diet quality (predictive validity). We anticipate that these aims will produce n effective tool for measuring nutrition literacy that can have wide application in health care and research settings.